Red Hat Bugzilla – Bug 815360
X crashes when switching users
Last modified: 2013-06-26 14:42:11 EDT
Description of problem:
[ 762.208] Backtrace:
[ 762.208] 0: /usr/bin/Xorg (xorg_backtrace+0x4a) [0x80abe5a]
[ 762.209] 1: /usr/bin/Xorg (0x8047000+0x69dd8) [0x80b0dd8]
[ 762.209] 2: (vdso) (__kernel_rt_sigreturn+0x0) [0xb773940c]
[ 762.209] 3: /lib/libpixman-1.so.0 (pixman_image_get_width+0x6) [0x48bb7356]
[ 762.209] 4: /usr/lib/xorg/modules/drivers/qxl_drv.so (0xb7612000+0x822b) [0xb761a22b]
[ 762.209] 5: /usr/lib/xorg/modules/drivers/qxl_drv.so (0xb7612000+0x55a4) [0xb76175a4]
[ 762.209] 6: /usr/bin/Xorg (0x8047000+0x10b90e) [0x815290e]
[ 762.209] 7: /usr/bin/Xorg (0x8047000+0xe2c2e) [0x8129c2e]
[ 762.209] 8: /usr/bin/Xorg (dixDestroyPixmap+0x14) [0x8072264]
[ 762.209] 9: /usr/bin/Xorg (0x8047000+0x538cd) [0x809a8cd]
[ 762.209] 10: /usr/bin/Xorg (FreeResource+0xec) [0x809b09c]
[ 762.209] 11: /usr/bin/Xorg (0x8047000+0x2b51f) [0x807251f]
[ 762.209] 12: /usr/bin/Xorg (0x8047000+0x3032d) [0x807732d]
[ 762.209] 13: /usr/bin/Xorg (0x8047000+0x1dc35) [0x8064c35]
[ 762.209] 14: /lib/libc.so.6 (__libc_start_main+0xf5) [0x48066635]
[ 762.209] 15: /usr/bin/Xorg (0x8047000+0x1df79) [0x8064f79]
[ 762.209] Segmentation fault at address (nil)
Fatal server error:
[ 762.209] Caught signal 11 (Segmentation fault). Server aborting
I get this when switching users in my KVM machine. I reproduced in also in a freshly installed VM. It seems easily reproducible.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. log in
2. hit switch user, display switches to gdm
3. wait a while (few seconds, max minutes)
4. X restarts
Created attachment 579534 [details]
Created attachment 579536 [details]
backtrace generated by abrt
Proposing as F17 Blocker.
When I switch from qxl driver to cirrus the VM does no longer crash.
While it is nasty, I don't think that this hits any of the F17 release criteria and I'm thinking this could be fixed with an update. Granted, it can't be fixed for the lives but I have a hard time seeing many people switch users in a livecd environment.
I'm a weak -1 blocker on this
Discussed in the 2012-05-01 blocker bug review meeting. Rejected as a blocker for F17 final because it doesn't hit any of the F17 release criteria, is specific to VMs and could be fixed with an update.
Fix up - tflink left it blocking.
Fedora Bugzappers volunteer triage team
Similar problem in bug #737924 - the reporter has done a bit of digging.
*** Bug 737924 has been marked as a duplicate of this bug. ***
Hans' comments from the F15 bug:
Steps to Reproduce:
1. Take a 64 bit F-15 vm, using spice of course
2. Make sure it is fully up2date
3. Login to the fallback gnome desktop
4. switch to a text VT
5. Wait a bit
Xorg crashes, and restarts taking you back to the gdm login screen
Being able to work on the text VT and then return to the open
I've been debugging this and the problem is that src/qxl_surface.c: qxl_surface_kill() gets called on a surface with a NULL host_image, moreover &surface->cache->all_images[id] != surface, so this smells like memory
corruption to me.
Cole: would https://bugzilla.redhat.com/show_bug.cgi?id=805017 be the same thing? Summary says 'Segmentation fault in anaconda when switching TTYs', but I've always just thought of it as 'the bug for when you switch to a VT in a VM and X crashes'.
Is http://article.gmane.org/gmane.comp.emulators.spice.devel/9534 intended to address this?
I don't think this was ever addressed in F17, and given that end-of-life is approaching I don't think it ever will be fixed. I haven't seen this issue on F18+, but if someone can reproduce on something newer, please reopen.